1. Field of the Invention
The present invention relates to a power converter and, more particularly, to a power converter with a controller that monitors and regulates variations in intended-to-be output voltages, sent as a feedback to the controller for output reliability.
2. Description of the Related Art
A power converter converts an input voltage to an output voltage to meet various demands of electric appliances. Power converters include AC to AC converters, AC to DC converters, DC to AC converters, and DC to DC converters. Power converters with a controller to regulate an output voltage for an input voltage are available in charging various electric appliances, including computers, cell phones, MP3, etc requiring different input voltages.
A conventional output-adjustable power converter includes a converter body with a circuit to regulate the input voltage for a desired output voltage. FIG. 5 shows a switching power converter including a converter body 1′ having a circuit (not shown in FIG. 5) for manipulating on an input voltage Vin for a desired output voltage value Vout. The converter body 1′ is connected at the same time with four resistors of different resistances, R1′, R2′, R3′, and R4′, the connection of which with the converter body is controlled by a selective-switching controller 11′. The output voltage Vout can thus be adjusted depending on different reference voltages due to the specifically selected connection of the resistors (R1′, R2′, R3′, and R4′) by the selective-switching controller 11′.
Although the above conventional power converter in FIG. 5 has the merit of simplicity in structure, in operation the selective-switching controller 11′ may nevertheless inadvertently jump to an undesired connection with any of the resistors and effects adversely the output. Furthermore, the output voltage Vout can potentially be adjusted even when an electric appliance is being powered by the output voltage Vout of the converter, leading to safety issues and damage to the electric appliance being used.
FIG. 6 shows a second conventional power converter with a converter body 2′ and a plurality of external resistors R5′ to R5N′ of different resistances, the connection of which with the converter body 2′ is selectively made depending upon desired output voltage Vout.
Even though the power converter in FIG. 6 has the advantage of a simple structure and a low manufacturing cost, it also has the same disadvantage stated before: during the time an electric appliance is being powered by the output voltage Vout of the converter, the potentially adjustable output voltage may cause safety issues and damage to the electric appliance being charged. Furthermore, external resistors are not conveniently portable, and such a power converter is inoperable in absence of external resistors.
FIG. 7 shows a third conventional power converter having a converter body 3′ and a plurality of output connectors 4′ to 4N′. The converter body 3′includes a multiple-conductor cable 31′ at an output end thereof. Each output connector of 4′ to 4N′ includes a resistor of 41′ to 4N1′ of different resistances, as well as a connector 42′ to 4N2′ for connection with electric appliances. One of the connectors of 42′ to 4N2′ is selected to connect to the multiple-conductor cable 31′ for regulating the output voltage Vout for a desired value.
Such a power converter illustrated in FIG. 7 assures more usage safety since no output voltage Vout is directed to the electric appliance being powered. However, multiple output connectors 4′-4N′ are not handy for users.
FIG. 8 shows a fourth conventional power converter of the type controlled by a micro computer. The power converter includes a converter body 5′ connected to a controller 51′ for adjusting output voltage Vout via a control button 511′. Such a power converter is handy without burdensome external components, and also allows output of various voltages through easy operation of a button. However, the button 511′ can be inadvertently activated by an unintentional contact.